Revert "Discard unread data of git cat-file (go-gitea#29297) (go-gitea#29310)"

This reverts commit ed5e0c8.

This causes Edit File on larger files to time out.

Author: brechtvl

modules/git/batch_reader.go

@@ -203,7 +203,16 @@ headerLoop:
 	}
 
 	// Discard the rest of the tag
-	return id, DiscardFull(rd, size-n+1)
+	discard := size - n + 1
+	for discard > math.MaxInt32 {
+		_, err := rd.Discard(math.MaxInt32)
+		if err != nil {
+			return id, err
+		}
+		discard -= math.MaxInt32
+	}
+	_, err := rd.Discard(int(discard))
+	return id, err
 }
 
 // ReadTreeID reads a tree ID from a cat-file --batch stream, throwing away the rest of the stream.
@@ -229,7 +238,16 @@ headerLoop:
 	}
 
 	// Discard the rest of the commit
-	return id, DiscardFull(rd, size-n+1)
+	discard := size - n + 1
+	for discard > math.MaxInt32 {
+		_, err := rd.Discard(math.MaxInt32)
+		if err != nil {
+			return id, err
+		}
+		discard -= math.MaxInt32
+	}
+	_, err := rd.Discard(int(discard))
+	return id, err
 }
 
 // git tree files are a list:
@@ -327,21 +345,3 @@ func init() {
 	_, filename, _, _ := runtime.Caller(0)
 	callerPrefix = strings.TrimSuffix(filename, "modules/git/batch_reader.go")
 }
-
-func DiscardFull(rd *bufio.Reader, discard int64) error {
-	if discard > math.MaxInt32 {
-		n, err := rd.Discard(math.MaxInt32)
-		discard -= int64(n)
-		if err != nil {
-			return err
-		}
-	}
-	for discard > 0 {
-		n, err := rd.Discard(int(discard))
-		discard -= int64(n)
-		if err != nil {
-			return err
-		}
-	}
-	return nil
-}

modules/git/blob_nogogit.go

@@ -9,6 +9,7 @@ import (
 	"bufio"
 	"bytes"
 	"io"
+	"math"
 
 	"code.gitea.io/gitea/modules/log"
 )
@@ -103,6 +104,25 @@ func (b *blobReader) Read(p []byte) (n int, err error) {
 // Close implements io.Closer
 func (b *blobReader) Close() error {
 	defer b.cancel()
-
-	return DiscardFull(b.rd, b.n+1)
+	if b.n > 0 {
+		for b.n > math.MaxInt32 {
+			n, err := b.rd.Discard(math.MaxInt32)
+			b.n -= int64(n)
+			if err != nil {
+				return err
+			}
+			b.n -= math.MaxInt32
+		}
+		n, err := b.rd.Discard(int(b.n))
+		b.n -= int64(n)
+		if err != nil {
+			return err
+		}
+	}
+	if b.n == 0 {
+		_, err := b.rd.Discard(1)
+		b.n--
+		return err
+	}
+	return nil
 }

modules/git/commit_info_nogogit.go

@@ -151,9 +151,6 @@ func GetLastCommitForPaths(ctx context.Context, commit *Commit, treePath string,
 			return nil, err
 		}
 		if typ != "commit" {
-			if err := DiscardFull(batchReader, size+1); err != nil {
-				return nil, err
-			}
 			return nil, fmt.Errorf("unexpected type: %s for commit id: %s", typ, commitID)
 		}
 		c, err = CommitFromReader(commit.repo, MustIDFromString(commitID), io.LimitReader(batchReader, size))

modules/git/pipeline/lfs_nogogit.go

@@ -170,10 +170,6 @@ func FindLFSFile(repo *git.Repository, hash git.SHA1) ([]*LFSResult, error) {
 				} else {
 					break commitReadingLoop
 				}
-			default:
-				if err := git.DiscardFull(batchReader, size+1); err != nil {
-					return nil, err
-				}
 			}
 		}
 	}

modules/git/repo_commit_nogogit.go

@@ -121,7 +121,8 @@ func (repo *Repository) getCommitFromBatchReader(rd *bufio.Reader, id SHA1) (*Co
 		return commit, nil
 	default:
 		log.Debug("Unknown typ: %s", typ)
-		if err := DiscardFull(rd, size+1); err != nil {
+		_, err = rd.Discard(int(size) + 1)
+		if err != nil {
 			return nil, err
 		}
 		return nil, ErrNotExist{

modules/git/repo_language_stats_nogogit.go

@@ -6,8 +6,10 @@
 package git
 
 import (
+	"bufio"
 	"bytes"
 	"io"
+	"math"
 	"strings"
 
 	"code.gitea.io/gitea/modules/analyze"
@@ -166,7 +168,8 @@ func (repo *Repository) GetLanguageStats(commitID string) (map[string]int64, err
 				return nil, err
 			}
 			content = contentBuf.Bytes()
-			if err := DiscardFull(batchReader, discard); err != nil {
+			err = discardFull(batchReader, discard)
+			if err != nil {
 				return nil, err
 			}
 		}
@@ -209,3 +212,21 @@ func (repo *Repository) GetLanguageStats(commitID string) (map[string]int64, err
 
 	return mergeLanguageStats(sizes), nil
 }
+
+func discardFull(rd *bufio.Reader, discard int64) error {
+	if discard > math.MaxInt32 {
+		n, err := rd.Discard(math.MaxInt32)
+		discard -= int64(n)
+		if err != nil {
+			return err
+		}
+	}
+	for discard > 0 {
+		n, err := rd.Discard(int(discard))
+		discard -= int64(n)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

modules/git/repo_tag_nogogit.go

@@ -103,9 +103,6 @@ func (repo *Repository) getTag(tagID SHA1, name string) (*Tag, error) {
 		return nil, err
 	}
 	if typ != "tag" {
-		if err := DiscardFull(rd, size+1); err != nil {
-			return nil, err
-		}
 		return nil, ErrNotExist{ID: tagID.String()}
 	}
 

modules/git/repo_tree_nogogit.go

@@ -58,9 +58,6 @@ func (repo *Repository) getTree(id SHA1) (*Tree, error) {
 		tree.entriesParsed = true
 		return tree, nil
 	default:
-		if err := DiscardFull(rd, size+1); err != nil {
-			return nil, err
-		}
 		return nil, ErrNotExist{
 			ID: id.String(),
 		}

modules/git/tree_nogogit.go

@@ -7,6 +7,7 @@ package git
 
 import (
 	"io"
+	"math"
 	"strings"
 )
 
@@ -62,8 +63,19 @@ func (t *Tree) ListEntries() (Entries, error) {
 		}
 
 		// Not a tree just use ls-tree instead
-		if err := DiscardFull(rd, sz+1); err != nil {
-			return nil, err
+		for sz > math.MaxInt32 {
+			discarded, err := rd.Discard(math.MaxInt32)
+			sz -= int64(discarded)
+			if err != nil {
+				return nil, err
+			}
+		}
+		for sz > 0 {
+			discarded, err := rd.Discard(int(sz))
+			sz -= int64(discarded)
+			if err != nil {
+				return nil, err
+			}
 		}
 	}